[neonkiwi]

You hypothesized about tissue damage from ultrasonic excitation, so this tangential post may be of interest. Tissue damage from ultrasound is an intentionally-caused phenomenon being used (and experimented with) in some non-invasive medical procedures, where focused energy can locally ablate a tumor for instance. HIFU, high-intensity focused ultrasound, is the technique: http://en.wikipedia.org/wiki/High-intensity_focused_ultrasou...